title: Niobium filter v. an aluminum filter.
authors.forename: G C
authors.initials: GC
authors.lastname: Stirling
authors.forename: A F
authors.initials: AF
authors.lastname: Holloway
mesh_terms: D000535:Aluminum; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D009556:Niobium; D011829:Radiation Dosage; D011861:Radiography, Dental / Q000295:instrumentation*
chemical_list: D009556:Niobium; D000535:Aluminum